A conventional inductor is best-known as planar inductor, and mentioned planar inductor may be utilized for designs of inductor pattern and trace pattern in a same plane. Owing to the reason that the planar inductor and the trace pattern are located in the same plane, a disturbance from parasitic capacitance is occurred and has to be overcome. Therefore, the chip size corresponded to the design pattern can not be decreased. Besides, the planar inductor merely forms a vortex structure instead of a toroid structure in a same radius.